If you want to strengthen your 'creative muscle' and experience what participating in a collaborative team process feels like, you might try out OpenIDEO. This online community composed of more than 40.000 creative thinkers worldwide engages in collectively solving real-world challenges for social and environmental impact.
OpenIDEO’s crowdsourcing innovation platform is open to anyone to participate in and collaborate on ideas.
Since 2010, OpenIDEO has hosted 16+ design challenges sponsored by companies, nonprofit organizations, universities, and governments. Community members can contribute in a variety of ways, from inspirational observations to snippets of code. Members themselves take the winning ideas forward. Anything added to OpenIDEO is available for remix and reuse.
source: Design Thinking Thoughts byTim Brown, Nurture Your Design Courage, One Challenge At a Time